1. Field of the Invention
This invention relates to a hook forceps apparatus for industrial endoscopes wherein a hook part is easily connected and fixed to a forceps shaft part side without being loosened.
2. Related Art Statement
Recently, there has come to be extensively used a medical endoscope whereby a body cavity interior can be diagnosed by inserting an elongated insertable part into the body cavity. Also, in the industrial field, an industrial endoscope is extensively used in the case of inspecting the interior of an engine or such pipe as of a chemical plant.
In the case of inspecting such object to be inspected as, for example, a gas turbine engine, as seen in U.S. patent application Ser. No. 966,308 (Japanese Patent Laid Open No. 78127/1980), generally a hook forceps is used to engage the tip side of an industrial endoscope insertable part inserted into an engine with one of rotary vanes. The hook part on the tip side of such hook forceps has been heretofore brazed or soldered to the forceps shaft part. In such case, the tip part of the forceps shaft part to which the hook part is fitted has been made of stainless steel. On the other hand, the hook part brazed or soldered to this tip part has been formed also of stainless steel.
The hook made of the above mentioned stainless steel can be connected with the forceps shaft part by brazing or the like and has a mechanical strength but will catch on something in the interior and will not be able to be pulled out in the case of being pulled out of an engine after being used. In such case, the forceps shaft side can be pulled out by dropping the hook part. However, in case the hook is made of stainless steel, if it remains within a turbine, for example, of a jet engine, it will damage the interior of the turbine and will not be desirable in respect of safety.
Therefore, the hook may be formed of aluminum of a low melting point and low hardness which will melt even if dropped or will be able to bend so as to cause no trouble in the above mentioned case and a female screw part to be screwed with a screw formed at the tip of the forceps shaft part may be formed in this hook but the dimension itselt of this hook is so small that the cost will become high in the step of forming the female screw, the mere screwing will loosen and therefore any other means of preventing loosening will be required.